Nope, the Guardian has not lost its marbles – our purpose here is not hailing weaponry of assassin-free assassinations. But from canned food to microwaves, and tampons to the internet, things either directly designed for the military sphere or else improvised to deal with wartime contingencies have turned out to have lasting peaceful applications. And, as we report, the core of a drone – a thermal-imaging camera aboard a remotely controlled aircraft – is being deployed not to kill people, but instead to protect birds. Having practised on hens, the RSPB now has the wherewithal to creep quietly up on rare bitterns and marsh harriers, and check they are OK without the noisy intrusion which might make them flee the nest. Such snooping on birds is a real advance, even though it would be frightening applied to people. But then, like so many inventions before it, the drone is just a clever idea, which can be used for evil or for good.